The broad objective of this research is to investigate the effects of sensory deprivation, in particular monocular and binocular lid suture, on the visual system of primates. In particular, the effects of monocular and binocular lid closure on the anatomy, electrophysiology, and behavior of a prosimian primate, Galago senegalensis, are being studied. We are also making comparisons between the results we obtain in galago with results of similar studies in the tree shrew and owl monkey. In brief, the following approaches are being or will be employed: (1) the anatomical changes caused by deprivation are determined through measures of cell size in the lateral geniculate nucleus, cell packing density in the superior colliculus and visual cortex, and changes in distribution of retino-geniculate and geniculo-striate axons. (2) the response of single neurons in the dorsal lateral geniculate nucleus of normal galagos are determined and compared to those in deprived animals. (3) behavioral changes caused by lid suture will be determined in galago and tree shrew through tests of visual perimetry and acuity.